Using Fixed Array Within A Structures?
Apr 19, 2010I have a class file which contains a structure like this.
<StructLayout(LayoutKind.Explicit)> _
Public Structure SampleStructure
<FieldOffset(0)> Public field1 As Int16
[Code]......
I have a class file which contains a structure like this.
<StructLayout(LayoutKind.Explicit)> _
Public Structure SampleStructure
<FieldOffset(0)> Public field1 As Int16
[Code]......
I am trying to create and initialize an array of structures of a fixed size. Each struct will be populated when a button is clicked. Here is an example of my struct:
public structure buttonStruct
dim x() as Boolean
dim y() as Boolean
[code]....
In my form_load function I am declaring the array of structs and:
Dim BtnStruct(15) As ButtonStruct
BtnStruct(0).Initialize()
[code]....
Whenever a specific button is clicked, I am trying to collect data and store it in the respective struct and so for example, if button 1 is clicked then I will store the data associated with button 1 into BtnStruct(0). The position of the button is stored in a public variable called BtnNum. If I attempt to store information in the struct inside another function as follows, I receive an error
BtnStruct(BtnNum).x(pos - 1) = temp "btnstruct is not declared. it may not be inaccessible due to its protection level"
Now all went well about from using the structure correctly. The working of the structure was perfect. How ever i missed Two important issues. The structure needed a fixed size of 10 items (9 in programming terms starting from 0) And also out of the 5 items allowed to be chosen as one of the member types for the structure a limit of 5 items of that particular type.
[Code]...
I have a Structure, and I am having trouble initialising it. Specifically when I try to populate the Vector3 variables, it tells me that they are Nothing, so I need to make them New when the array of this structure is declared.[code]Structures cannot declare a non-shared 'Sub New' with no parameters.I have no parameter to supply, and this will be an array so I'm not even sure how I would supply it.The second option to fix the error is to make the Sub New shared, but then I get other errors: Cannot refer to an instance member of a class from within a shared method or shared member initializer without an explicit instance of the class.Does anyone know how I can resolve this. My end goal is to have an array of this structure type with the Vector3s ready to use.
View 6 RepliesI need to have an Array of UDTs(Structures). Elements have to be added (at end) and removed (from anywhere). The different values of the elements need to be changeable.
I know how to implement it as an oldstyle array, but wouldn't it be better to implement as a List ( of T)? and if yes is such a procedure possible?[code...]
I have 2 Structures
Public Structure One
Public ItemOne As String
Public ItemTwo As Integer
End Structure
[Code]...
Results In an Unhandled exception. Bad Record Length. and then If I close it and reopen it I get an 'Unable to read beyond end of stream' error. So what is the best way to save an array of structures? Binary Reader/Writer? and why does this way not work (Even if its derived from VB6)
I have an array of structures:
Structure stCar
Dim Name As String
[code].....
how to go about getting data populated from a data grid view to an array of structures? I have a data grid view with 6 fields and 10 records that match elements in my array. I declared a list of songs based off of my structure Song.
[Code]....
Is an ArrayList the same thing as a Structure (i.e. 'array of records')? If they're not the same think, what't the difference?
View 3 RepliesI am getting an error when helping someone with their code. They are trying to create an array of Items, but gets an error at ItemStruc(counter).ItemName = Contents(0)
I am not sure why. >_>
Structure is as follows:
public structure Item
dim itemName as String
[Code].....
�On load read data from units.txt into an array of structures;�Allow the user to choose a major and then add units to a study plan.Note your program must not allow the user to add units not in the major and a unit can only be added once to a study plan;�Save student first name & last name, student number, unit codes to a user selected file (e.g. fred.txt); �Allow the user to select a student file to load using a common dialog control ;�Display the units for that student.
The program must have the following features:�It must use a common dialog control for saving data;�The program must have at least one general procedure; �The program must demonstrate the use of an array (array of structures recommended).I've attached a copy of the text file needed to be loaded.
I've learned about and understand HOW to do a bubble sort (theoretically), but I can't seem to wrap my head around how to use a bubble sort with array structures. I'm supposed to be able to sort the inputted student information (via textfile) using bubble sort and display the result in a listbox. Buttons for Sort by last name, sort by gpa, & sort by letter grade.
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I have a structure which includes this...
Structure MasterStruct
<VBFixedArray(98)>
End Structure
When I create the code to initialize the Sections array like this...
Dim MasterX as MasterStruct
Dim Temp as Integer
For Temp = 0 To 98
MasterX.Sections(Temp) = 0
Next
VS 2008 tells me that MasterX.Sections "is not an array or method, and cannot have an argument list."
[code]Is there any other solution by which we can initialise the array members using new?
View 5 RepliesWhat i am doing is inserting the first element in array3 into the first index of array4
then im checking second index of array3 and if this is the same as the 1st array then dont insert into array4 as this will be a duplicate.[code]...
I am trying to write a program that will use a Structure with <VBFixedString(4), VBFixedArray(10)> Public Test1() As String. Back in vb6 it was in the Type statement as Test1(10) as string *4 When I hit the line ".Test1(X) = TB1" i get the following error:
Object reference not set to an instance of an object.
[Code]...
I am trying to get the data from the text file to load into an array of structures and then be displayed in a listbox on FormLoad with no luck, all I get is a blank listbox.
Code:
Public Class frmMemList
'Create a structure to which data from text file MEMBERPHONES.TXT will be read.
Structure MemberList
[code]....
I am really struggling lately for some reason. I do not know why, but I can not get simple programming code to work, usually due to simple mistakes. Anyway, enough about that.Here is my code, I am trying to get the data from the text file to load into an array of structures and then be displayed in a listbox on F
Public Class frmMemList
'Create a structure to which data from text file MEMBERPHONES.TXT will be read.
Structure MemberList
[code].....
I need to create a collection of millions of objects, each object has 3 double and one integer fields.If I remember (after more than 20 years without using C) in C you would allocate enough memory using a struct and an array, and read all the file content in one shot.In VB I created a class with the 4 members, and this constructor:
Sub New(BR As IO.BinaryReader)
X = BR.ReadDouble
Y = BR.ReadDouble
[code]....
I coded anything but I remember when using VB6 or Pascal/Delphi we used to define records/ structures with fixed length fields, then write those structures to a file knowing that they would always be the same length. You could then open a particular record within the file or simply find out how many records existed by reading the file length.From what I understand, it seems that such methods are depreciated in VB.NET and such structures are written as a stream.Does it now mean that we can define things like variable length strings and not need to worry about buffers or boundaries?Is it possible to read through such files and pick out individual records? Are there methods of determining how many records that exist in a file? What I'm looking to do is simply store multiple records of a structure in a file then retrieve them into an array so I can manipulate their order by sorting the array and search within the array. This is only a learning project so it is unlikely that the resultant array is going to be large, although if this is not generaly a good method of doing this then it might be interesting to fidn out what is. So far, I have read that they way to write a structure to a file is to "serialises" it and then write the bytes - is this correct?[code]
View 5 RepliesThese are the directions for the assignment.So far I am able to get the file read and printed onto a list box.The book we have for the class does not clearly talk about using the array of structure method with formatting an imported text file.After that I'm pretty much having a bit of trouble with everything else.I know I can figure most of it out but what I'm having a big amount of trouble with is the array of structures that he wants.I know that when I have the file imported that I need to save it temporarily and go through it and at every ":" put it in an array and save that spot and then keep scanning through the file. I know it is going to be a for loop using the index to count through but I'm not sure if how to start it.This is how the text file that he wants sorted out looks.
Ally Gators:Tim Tebow:240:280:250
Ally Gators:Albert Gator:150:175:222
Ally Gators:Joe Cool:195:220:217[code]...........
Correct the problems with this function, and then extend it so that it also returns a usable array of pointers to some structures.
The extended version of this function should: Maintain the same "char *" return type which returns a pointer to a usable, for storing a C string, memory buffer.
In addition, also return a usable array of pointers to structures. This array of pointers is of variable and random length, which must be obtained using GetNumberOfSomeSeqsToGenerate(), which is called, ONLY, from within this new extended version of the function.
The type of these structures and the function that should be used to get these structures are defined as follows:
typedef struct {
char* name; /* '\0'-terminated C string */
int number;
} SomeSeq;
[CODE]...
The file structure is fine for retrieving data from the file but when I go to write data to the elements and hit any of the fixed array elements, I get an exception error. this has got to be a sytax problem I am just not seeing.
It seems that I am not addressing the array member correctly yet the same logic pulls it properly from existing records on file.
in a Module I have the structure as follows:
Structure INVOICE
<VBFixedString(6)> Public NUM As String
<VBFixedString(2)> Public SYMBOL As String
[Code]....
I have a structure called 'Scheme' and in my program I want (ideally) an ArrayList of 'Schemes' (so i can add, remove schemes etc.). However, within the 'Scheme' structure, I want to have an ArrayList of 'Item''Item' is another structure. Are there any solutions out there for iterating through these arrays quite easily?
How can I easily add multiple Items to a Scheme and mutliple Schemes to my Scheme array. Code is below. When I try to add Items to a Scheme, I get the 'Object not set to a reference of an object, try the 'New' keyword', but you cannot declare 'New' keywork within a structure.
[Code]...
I have a long string like this
dim LongString as String = "123abc456def789ghi"
And I want to split it into a string array. Each element of the array should be in 3 characters length[code]...
I read in the Book "Mastering Microsoft Visual Basic 2008" about "User-Defined data types".The example given is creating a Structure as follows.I wanted to check that so I wrote all the code given; I used a TextBox and a Button for this.(I didn't include the "CheckDate" here; that is in the book)
Structure CheckRecord
Dim CheckNumber As Integer
[code]....
The problem is this does work.What I get is "00000". and I found out that the "Checks(4)" Array does hold any value ie: on keeping the cursor over that, it shows "CheckAmount 0.0, CheckNumber 0 , CheckPaidTo Nothing ".
This is my code in vb.net 2010:
Structure feature_s
Public feature() As Integer
End Structure
[CODE]............
I keep on getting a error "object not set to an instance of an object" i am puzzled by this since there are no errors until i run the program. I redim the array. the build is fine. the exception is handled. and the structures and "dims are all global"
I'm attempting to create a list of structures that contains a list of structures. I can't seem to figure out how to properly allocate the object for the inner list of structures. I expect the outer list of structures to have a couple thousand entries and the inner list of structures to be fairly small at 2 to 10. Both lists will grow over time but the number of elements within the inner list will be constant for an instance of the outer list. Meaning, if an instance of the outer list has 2000 entries each of those will have the same number of elements on the inner list, say 4 entries.
Here is a simplified code fragment. This fragment makes no attempt to create the instance of the inner list "StructBlist" since I can't figure out where to put it. Tried "New List(Of StructB)" in the declaration as well as "Alist(0).StructBlist = New List(Of StructB)" but neither works.
Public Class Form1
Structure StructA
Dim FieldA1 As Integer
[Code]....
What is the different between these 2 structures?
Structure INPUT
Public dwType As InputType
Public mi As MOUSEINPUT
Public ki As KEYBDINPUT
End Structure
[Code]...
Structure TextureStruct
Dim unk1 As ULong 'always 0x70007
Dim unk2 As ULong 'always 0x70007
Dim unk3 As ULong 'always 0x70007
Dim unk4 As ULong 'always 0x70007
Dim unk5 As ULong 'always 0x70007
Dim unk6 As ULong 'always 0x70007
[Code]...